water pump/ tell tale issues

[iceman88]

i have a 82 7.5 hp johnson and I just replaced the water pump and i am still not getting any flow out of the tell tale, and i am still having cooling issues. Not sure what else could be wrong any suggestions.

 

[Vic.S]

Re: water pump/ tell tale issues

You have checked that the telltale is not blocked .

You are sure you have assembled the pump correctly and that the impeller drive key is in position?

You are sure that the water tube has entered the top of the water pump and that the grommet is in good condition if not new.

Did you connect a hose onto the water tube and make sure you could get a water flow through the engine power head and the telltale?

I would suspect a likely problem is that the grommet at the top of the water tube has been squeezed, by corrosion around it, until it has completely blocked off the top of the water tube.
It is problem I know only too well with my '84 6 hp and I beleive the earlier 7.5 is exactly the same.

Unfortunately it requires the power head to be removed to access it.

Even when all that is sorted you may find the water passages in the cylinder head are blocked ... not had to unblock mine yet but I have seen pictures of them well blocked.

 

[Vic.S]

Re: water pump/ tell tale issues

Found a picture of the offending grommet at the top of the watertube.

 

[iceman88]

Re: water pump/ tell tale issues

Thanks I think that is what the problem is i ran a rod up and could feel the blockage. How difficult was it to pull the power head cause I am thinking of doing it my self, any tips would be helpful.

 

[Vic.S]

Re: water pump/ tell tale issues

Ah you could feel something rubbery up there !

Its not what I would call difficult, Breaking the joint was probably the most difficult but once you realise that the inner exhaust tube stops you from rocking it sideways and that fore and aft is the way to do it there's no real problem.

you'll need a new gasket.

 

[kenmyfam]

Re: water pump/ tell tale issues

Salt water motor ???

 

[Vic.S]

Re: water pump/ tell tale issues

Mine is, not sure about the one in the picture its not mine.

"ALL EVINRUDE AND OMC MOTORS ARE SALT WATER ENGINEERED" at least that's what the brochure says! see at the bottom of the page

 

[iceman88]

Re: water pump/ tell tale issues

yeah I do not know if it was run in salt water or not got it for free but nothing is truly free I guess. I was actually able to puncture the grommet with the rod and tested it and water flows but at high speeds it still overheats so I guess I have to tear it down and replace it. Or could there be another problem? The big question is that i my engine it looks like I have to remove every thing fuel pump, electrical housing, and shift linkage, ect to get access to the bolts. This is the part i am most concerned with, did you need to do the same... and how was it if you did. And thanks for everything so far Vic your keeping this broke college students dreams of catching big fish going lol

 

[Vic.S]

Re: water pump/ tell tale issues

Some years since I last took the power head out but I don't remember having to remove much else ( apart from the gear case) I did not even detach all the wiring, just enough to get at what I wanted to get at.

You may also have to take the head off to clear out the water passages. That figure of 8 passage around the head can get blocked.